It is an amazing thing when a stray comment, almost a throw-away line, causes a lot of other ideas to suddenly form a coherent whole. That happened to me earlier this month.
I have been interviewing various smart friends for a “distance learning” class that Arizona State University asked me to create regarding risk, safety, and crowd management at live events. Right in my wheelhouse, and the conversations have been interesting and informative.
One discussion in particular, in which we got into a bit of crowd management theory, yielded my epiphany. 
Because I’m not the sort of person to keep a mind-blowing revelation to myself, I am sharing it, with some basic context, in the video linked here.
Go ahead, click on the arrow to watch the video. Maybe a light bulb will turn on for you too.
In a nutshell, I am proposing that modern crowd management theory, which has evolved from John Fruin’s four “crowd dynamics factors” of time, space, information, and energy, through Keith Still’s DIM ICE model (design, information, and management of ingress, circulation, and egress), needs a further revision. Event organizers’ crowd management planning must also account for the crowd’s own reasonably foreseeable expectations regarding the event and all its circumstances.
The image at left is a visual representation of my proposal. (Say it out loud, you’ll get it.)
I hope you find the video content to be relatively easy to digest. This clip clocks in at just over 16 minutes. In the future, I’ll take the time to make them shorter.